Compressor



March 10, 1936 J. c. M CUNE El" AL .cbMPREssoR Filed Feb. 19,1932

'2' Sheets-Sheet 1 March 10, 1-936. J. c. McCUNE AL 1 2,033,437

COMPRESSOR Filed Feb. 19, 1932 2 Sheets-Sheet 2 Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE COMPRESSOR Application February 19, 1932, Serial No. 594,116

17 Claims. (Cl. 230-184) This invention relates to fluid compressors and more .particularly to compressors of the reciprocating type.

' One of the objects of the present invention is to provide a novel compressor of the type referred to above.

Another object of the invention is to provide in a compressor of the above character, a novel arrangement of parts permitting an increased delivery of fluid to the compressor during-the suction stroke thereof, thereby resulting in unusually eflicient operation at widely difierent speeds.

Still another object is to provide a novel intake valve construction for a reciprocating compressor which shall be not only simple in construction and economical of manufacture but also so constituted as to materially increase the efliciency of the compressor.

A further object is to provide in a compressor of the above character, a novel distribution of intake ports and passages in the wall of the cylinder of the compressor and adjacent thereto, for the purpose of substantially increasing and rendering more uniform the lateral flow of fluid into the compressor during operation thereof.

Still another object is to provide a novel driving arrangement for a compressor permitting the same to be drivably connected in a simple and eflicient manner with a portion of the gear train of an internal combustion englne.

A further object is to provide in a compressor of the above character, a novel arrangement of elements for lubricating the moving parts of the compressor from the pressure lubricating system of an internal combustion engine, together with a novel sealing means for preventing escape of the lubricant and consequent loss in pressure thereof at the point of introduction of the lu bricant to the compressor.

A still further object is to provide a novel compressor structure having relatively few parts, arranged in such a manner as to result in a substantially light-weight and compact construction, capable of manufacture at a relatively' low cost, and readily adapted for installa-' tion on existing'types of internal combustion engines.

The above and other objects will appear more fully hereinafter from the following detailed description when taken in connection with the accompanying drawings which is illustrative of one form of the invention. It is to be expressly understood, however, that the drawings are for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

Referring to the drawings wherein similar reference characters refer to similar parts throughout the several views,

:Fig. 1 is a substantially vertical section of a compressor constructed in accordance with the principles of the present invention;

Fig. 2 is a section taken on line 2-2 of Fig.

1 showing the piston at the limit of its suction stroke; and I Fig. 3 is a horizontal section taken on line M 3-3 of Fig. 2 and illustrating the arrangement of the intake manifold with respect to the intake ports.

" Referring more particularly to Fig. 1, a compressor embodying the present invention is disclosed thereinas being of the twin type and constituted by a cylinder block 4 providingcylinders 5 and 6, in which pistons 1 and 8 respectively are mounted to reciprocate.

In order to reciprocate each piston in its associated cylinder a suitable crankshaft 9 is provided, rotatably mounted, as by means of ball bearings l0 and .H' associated witheither end of the crankshaft, in a crank case 12, to

which the cylinder block 4 is secured. The crankshaft, as shown, is provided with a pair of cranks l3.and M to which the pistons l and 8 are respectively connected as by means of connecting rods I5.

Means are provided for rotating the crankshaft 9 and preferably such means is constituted by a portion of the gearing connected to an internal combustion engine. As shown, such means comprises a gear I6, adapted to mesh with a. suitable engine driven gear, not shown,

. the gear I6 being housed within a casing I! forrr ng a portion of the engine casing, and being splined or keyed to a shaft [8 rotatably mounted as by means of bearings 19 in the casing ll. Integrally formed or otherwise connected with one end of the shaft 18 are teeth 20 which are drivably connected by means of a suitable yielding torque transmitting device 23 with corresponding teeth 2| formed on a gear 22 connected with the crankshaft 9, this construction thus forming a yielding driving connection for the compressor.

Suitable exhaust valve mechanism for each cylinder is provided, and as shown is positioned in aremovable head 24 associated with the top of the cylinder block 4i lach exhaust valve is constituted by a disk or plate 25 located in intercommunicating chambers 26 'and is resiliently urged into engagement with a valve seat 21 by to the wall portions is such as to direct the.- incoming fluid against either or both of the wall portions, dependent upon whether either or both of the intake openings are employed, in order to efficiently direct the fluid toward the intake 5 ports with a minimum loss in energy due to eddy currents and other factors which are detrimental to high efliciency operation of the compressor at relatively high speeds. This construction thus provides a streamlined passage for the entrance of fluid, which it will be appreciated,

' results in a simple and efficient method of conports 3i are arranged in the wall of each cylinder and so positioned as to be partly or wholly uncovered by the pistons atthe limit of the suction strokes thereof. Preferably, however, these ports are arranged so as to be uncovered approximately fifty percent of their area, as

shown in Fig. 2, it having been determined that for this port area, the efllciency of the compressor a maximum. It has further been determined that in a compressor of this character, wherein the intake ports are arranged in the side walls of the cylinder in order. to utilize the uni-flow principle, a substantially increased efficiency is secured by employing a ration of total piston displacement to effective piston displacement of]1.09 or less, and a ratio of total piston displacement to effective port area of 24.1 or less. The intake ports are, therefore, preferably arranged as above set forth,

that is, are so located that only one-half of the area thereof communicates with theinterior of the cylinder at the limit of the suction stroke of the piston, and the size of said'ports and the number othereof ispreferably such asto satisfy the above mentioned ratios. Although it has been ascertained that when the above mentioned ratios are-adhered to, a compressor having a substantially high operating eiflciency is secured, it is contemplated that other ratios maybe employed if desired. As shown more particularly in Figs." 2 and 3, the ports 3| are positioned in the same plane and are spaced the remote sidewalls of said cylinders, an auxiliary port 32 is preferably positioned intermediate two of the ports 3| in order-to conduct a substantially equal amount of fluid to such side walls as is conducted through the remaining fluidor lubricant under pressure to this chamducting the fluid to the compressor while permitting the useof a manifold to protect the intake ports from dust, water, etc.

Since, as above stated, the compressor isadapted for use in connection, with internal combustion engines it is highly desirable to utilize the pressure lubrication system of the engine in order to lubricate the moving parts of 'the compressor, thus avoiding the added expense and inherent difliculties present in providing a separate pump and lubricating system for the compressor. To this end, each of the connecting rods I5 is provided with internal lubrication ducts 38 which communicate with ducts 39 in' the crankshaft," these last named ducts being in communication with a chamber 40 formed in one end of the crankshaft. In order to conduct her, a cap 4! is removably associated with the crank case l2, the said cap being provided with a duct 42 communicating with the chamber 40 and with an enlarged opening 43 adapted to be connected with the pressure lubricating system of the engine. Since theoap 4| is stationarily mounted with respect to the rotating crankshaft 9, means are provided betweenthe said cap and the crankshaft for preventing leakage 3 equally about the wall of the cylinders. 0n

ports. It is also pointed out that each of the cylinder block, surrounds each of the cylinders,

and is spaced therefrom in order to providean inlet chamber 34. As shown, this manifold is provided with a wall comprising portions 35 and 36 which slope inwardly toward a vertical plane intermediate the two cylinders, the said portions preferably meeting at an obtuse angle. Adiacent the outer extremities of the wall portions a pair of intake openings 31 are provided and the location'of these openings with respect the chamber 40 which might effect a substantial of the fluid or lubricant under pressure from reduction in the pressure 'of the lubricant and consequent inefll'cient lubrication of the parts positioned in a groove. located in a portion 45 formed integrally with the cap and projecting into the chamber 40, the said ring. being preferably resiliently expanded into'intimate contactwith the peripheral wall of the chamber. A lubricant drain 46 is preferably provided in the lower portion of the crank case l2 which is adapted to register with a duct 41 formed in the casing I! in order .to conduct the lubricant back to the engine pump.

There is thus provided by the present invention a novel fluid compressor of the reciprocating uni-flow type, the construction and relation of the component parts of which are such as to result in an unusually efllciently operating structure of this character. By providing the relatively simple inletport construction a great saving in material and weight is secured. It is also to benoted that by the relatively irregular positioning of such inlet ports andthe location, and shape of the cooperating intake manifold, a substantially uniform lateral flow of fluid into the cylinders is secured with a minimum loss in energy dueto; eddy currents and other causes affecting the velocity of the fluid to be conducted to the compressor, thereby resulting in an increased mass of fluid to be compressed, even though the compressor is operating at relatively high speeds. There is also provided by the novel lubricant sealing means a relatively simple and emcient method of conducting a lubricant under pressure to the moving parts of the compressor with a minimum loss in the pressure head of the lubricant supply. It is also to be pointed out that a compressor constructed in such a manner that the ratio of total piston displacement to efiective piston displacement is 1.09 or less and with a ratio of .total displacement to effective port area of 24.1

or less yields a substantially high overall opcrating efliciency and at the same time permits of some latitude in the selection of the size and number of intake ports in order that the struc ture may be readily adapted for various uses and combinations without any loss of efliciency.

While there is shown and described only one embodiment of the invention, it is to be expressly understood that the same is not limited thereto but may be embodied in various other forms. Reference willtherefore be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. A compressor comprising a crank case, a crankshaft rotatably mounted therein, a cylinder block provided with a pair of cylinders mounted on said crank case, a piston reciprocatingly mounted in each cylinder, each of said pistons being drivably connected with said crankshaft, a plurality of intake openings located in the wall of each cylinder and positioned to be partly uncovered by each piston at the limit of the suction stroke thereof, a hollow casing communicating with the intake openings surrounding said cylinders and formed integrally therewith, said casing having a port communicating with the atmosphere, said port being positioned adjacent one of said cylinders, and a wall formed with said casing sloping inwardly from said port to a point between said cylinders to form a streamline passage for the entrance of air to said casing and cylinders.

2. A compressor comprising a pair of cylinders arranged side by side, a piston reciprocatingly mounted in each of said cylinders, exhaust ports for said cylinders, valves for controlling said exhaust ports, a plurality of intake ports for each cylinder located in the wall thereof and positioned to be partly uncovered .by said pis-' said cylinders and communicating with said intake ports, said manifold having awall' portion spaced from and substantially parallel to the common vertical plane of said cylinders, said wall portion sloping inwardly from each of its outer ends toward the center thereof.

3. A compressor having a cylinder, a piston reciprocatingly mounted therein, an exhaust port for said cylinder, a valve for controlling the exhaust port, a plurality of intake ports arranged in the wall of said cylinder, all of said-intake ports being positioned to be partially uncovered by said piston at the limit of the suction stroke thereof, at least two of said intake ports beingunequally spaced around the wall of said cylinder with respect to the remaining intake ports, and a manifold surrounding said cylinder for conducting air to said intake ports.

4. In combination with a cylinder having a piston mounted to reciprocate therein, an intake manifold surrounding said cylinder, said wall formed integrally with said manifold and sloping from said opening toward said intake port for directing air from said opening to said port during the suction stroke of said piston. 5. The combination with a compressor of the ,type having a reciprocating piston, of a cylinder therefor having a plurality'of intake ports arranged in a circle in the wall thereof, all of said ports lying in a plane perpendicular to the axis of said cylinder, some of said ports being unequally spaced around the wall of said cylinder with respect to certain others of said ports and a manifold surrounding said cylinder for conducting air to said intake ports.

6. In combination a cylinder, a piston mounted therein, means including a crankshaft for revcylinder for conducting air to said intake ports.

7. In combination a cylinder, a piston mounted therein, means for reciprocating said piston including a crankshaft, an exhaust port for said cylinder, a valve for controlling said exhaust port, a series of intake ports for said'cylinder,

said last named ports being positioned around the wall of said cylinder and arranged to be simultaneously partially uncovered by said piston, there being a greater number of intake ports on one side of the median plane of said cylinder perpendicular to the axis of the crankshaft than on the other side, and a manifold surrounding said cylinder for conducting air to said intake ports.

8. A compressor having a crank case, a cylinder removably connected with said crank case, a head removably associated with said cylinder, a piston reciprocatingly mounted in said cylinder, an exhaust port located in said head, a valve for controlling said exhaust port, a series of intake" ports arranged around said cylinder in the wall thereof for conducting air into said cylinder during the suction stroke of said piston,

at least two of said intake ports being arranged closer together than the remaining ports, and a manifold surrounding said cylinder for conducting air to said intake ports.

-'9. In a compressor having a crank case and a crankshaft, means comprising a plurality of ball bearings for rotatably mounting said crankshaft in said crank case, a recess formed in one end of said crankshaft, a. cap secured to the a crank case supporting said cylinder, a crank shaft drivably connected to said piston, means including a bearing unit for rotatably mounting said crankshaft in said crank case, and means for conducting a fluid under pressure through said crankshaft comprising a removable cap connected with said crank case, said cap being provided with a fluid conducting duct and fluid sealing ring associated with said crankshaft for preventing loss of fluid through said bearing 1 unit.

11. A compressor comprising a block having a pair of cylinders arranged side by'side therein. pistons in said cylinders, intake ports for said cylinders, a casing enclosing all of said ports,

' and an inlet opening in said casing so arranged with respect to said cylinders as to, direct air into said casing in a path substantially parallel to the common plane of said cylinder axes.

12. A compressor comprising a block having a plurality of cylinders therein, pistons in said cylinders, intake ports for said cylinders, a casing enclosing all of said ports, said casing having two adjacent straight wall portions meeting at an obtuse angle, and an intake opening to said casing adjacent one of said straight wall portions.

13. A compressor comprising a pair of cylinders, pistons in said cylinders, exhaust ports for said cylinders, a series of spaced intake ports in each of said cylinder walls, the ports in each of said cylinders being more widely'spaced on the side adjacent the'other cylinder than on the opposite side, and a manifold surrounding both of said cylinders for conducting fluid to said intake ports, said manifold being spaced a greater distance from the cylinder portions having widely spaced intake ports than from the other cylinder portions.

14. A compressor comprising a pair of cylin-i ders, pistons in said cylinders, exhaust ports for said cylinders, a series of evenly spaced periph eral intake ports in each cylinder wall; an additional intake port in each cylinder wall on the side remote from the other cylinder, and a manifold surrounding both of said cylinders for conducting air;to said intake ports.

15. l 1n a compressor having a casing defining a pluralityof cylinders and a crank case, pistons in said cylinders, and intake and exhaust ports for said cylinders, a crankshaft connected to said pistons for actuating the same, said crankshaft being hollow throughout at least. a portion of its length to provide a passage for fluid,

means including a bearing unit for supporting one end of said crankshaft on said casing, said bearing unit being provided with stationary and rotatable races carried by said casing and crankshaft respectively, a chamber formed in said crankshaft and communicating with said pascrankshaft being hollow throughout at least a portion of its length to provide a passage for .fluid, a, chamber in the end of said crankshaft communicating with said passage, a closure for the end of said casing having a hollow projection extending into said chamber for conducting fluidthereto, and sealing means between said projection and said chamber walls.

17. A compressor comprising a block having a plurality of cylinders therein, pistons in said cylinders, exhaust ports for said cylinders, a series of intake ports in each cylinder wall, said intake ports being more closely spaced on one side of said cylinder than on the other, a casing enclosing all of said intake ports, said casing having a wall portion sloping inwardly toward said cylinders, and an inlet to said casing adjacent said wall portion and so arranged with respect to said wall portion as to direct air entering through said port along said wall portion toward said cylinders.

JOSEPH C. MCCUNE. STEPHEN JOHNSON, JR. 

